@Maenad Found it ! (it was in fact just above what I posted :/ )
There's as well Blanchard's "explanation".
Somewhere else in the book she sais that for Blanchard it's actually like sexual intensity in an married couple. https://witches.town/media/KK31WYN659YCoGXJNOc https://witches.town/media/QPUUhmp3dw9l8I5sQNM

@Mawloc interesting! I don't like this part as much.

I like the idea of "who do you focus on in fantasies? your body or your partner's? what does that look like?" as a avenue to explore but obv transition is about way more than sex or it would look way different socially.

Honestly, I think it "went away" for me because I just learned how my sexuality worked ("it's okay to pretend to have a penis" "it's okay to prefer sex that isn't piv" "it's okay to be the aggressor even if you have a female body") and my sexual "block" went away, but I'm lucky in that that was POSSIBLE for me.